While the Novartis trial was happening, Lustig and others were working on ways to revive hearing in genetic types of hearing loss. In 2019, Lustig and his collaborators showed that OTOF gene therapy might be used to restore hearing in mice lacking the otoferlin protein. A separate group in Germany published similar findings in 2021, showing that the outcomes might be reproduced.
“For any gene therapy to work, your goal cell needs to be alive and never dead,” says Jeffrey Holt, a professor of otolaryngology and neurology at Harvard Medical School, who studies gene therapy for deafness but isn’t involved with the present trials. Many genetic mutations linked to deafness cause the hair cells within the inner ear to die, but OTOF mutations leave these cells intact. “That bodes well for this strategy,” he says.
While the trials are open to participants as much as age 18, Holt says it might be best to present the gene therapy earlier in life. “The auditory system goes through a maturation process, and in the event you deliver this at a stage after that system has already matured within the absence of sound, we do not really understand how it will handle that latest input of data,” he says. This is why adults have a harder time learning a latest language than children do. Children’s brains are highly plastic—meaning they will easily form latest connections and learn latest things.
Doctors recommend cochlear implant surgery before age 3 in order that children can learn sounds when their language skills are developing, although older people can still profit from the devices.
While the present trials are for a rare form of deafness, researchers with the businesses think other genetic mutations that cause deafness might be addressed with gene therapy.
But not everyone thinks deafness needs medical interventions. Jaipreet Virdi, a historian of drugs, technology, and disability on the University of Delaware who’s deaf, says that gene therapy is an extension of the controversy that began within the Nineties over cochlear implants, which some Deaf people view as a threat to the Deaf community. They argue that implanting Deaf children before they’ve a likelihood to amass language denies them autonomy and access to Deaf culture. “Erasure before selection is presented—to a person, not their parents—is problematic,” Virdi says.
Wyatte Hall, a psychologist and public health researcher on the University of Rochester who studies language acquisition’s role in deaf people’s health and is deaf himself, says hearing parents with a toddler who’s deaf may even see medical interventions or technology as a solution to help their child fit into the world as they understand it. But Hall says Deaf people contribute to the richness of society. “As long as deaf people has been around on the earth, people have at all times been attempting to fix us,” he says. “The indisputable fact that we’re still here suggests that there remains to be some form of inherent evolutionary value in us, and our differences contribute to the world all of us live in.”
He’s not necessarily against cochlear implants and gene therapy, but he doesn’t think parents should limit access to sign language in favor of a medical-only approach. When working with families of Deaf children, he emphasizes a “each” approach—using technology and sign language. “If gene therapy or technology doesn’t work,” Hall says, “sign language is there as a developmental safeguard.”